Quantum 400W Dimmable Ballast The Quantum Dimmable Ballast brings quality, efficiency, and high intensity illumination to your garden. With a Power Factor of 99.9%â€”a highly stable output frequencyâ€”the Quantum Dimmable ballast lets you run your lamps at the strength you need allowing you to control your light spread. Rigorously engineered, it features a resin cased circuit board with a sealed bearing fan so it will run cooler than any other ballast and itâ€™s been tested to withstand the extreme atmospheric conditions of virtually any growing environment. The Quantum Dimmable Ballast is silent, generator-ready, efficient, and cool-runningâ€”this is one cool ballast. Run at 100%, 75% or 50% power (400W runs at 100% and 75%) Strike both metal halide and high pressure sodium bulbs Accepts 120V/240V with no wiring needed (both cords included); 208V-configurable with electrician assistance Accepts 50 Hz to 60 Hz with no extra wiring needed Runs 15% cooler than other digital ballasts on the market Has a continuous power factor of 99% The most stable output frequency of any ballast Higher lumen output than magnetic ballasts Can run efficiently on generators without flickering Resin sealed circuit board for high humidity inst